3rd B2 Practice Exam Alt A Questions
And Correct Answers
In an impulse steam turbine nozzle, the following events take place - Ans--1)
The steam pressure decreases
2) The enthalpy of the steam decreases
3) The velocity of the steam increases
4) The volume of the steam increases
Turbine nozzles convert heat energy into: - Ans--Kinetic Energy
The purpose of the bucket or moving blade on the rotor is to convert the
____________ energy of the steam into ________ energy - Ans--Kinetic
into mechanical
In an impulse turbine as the steam passes through the moving blades the
________ drops but the ______ remains the same. - Ans--Velocity drops
and pressure remains the same
The pressure at the outlet from the moving blades is the same as the
pressure at the inlet to the moving blades in __________ turbine. - Ans--An
impulse turbine
Steam turbine stationary nozzles serve to - Ans--1) Decrease steam
pressure
4) Increase steam velocity
On an extraction turbine the extraction pressure is - Ans--Maintained
Topping Turbine - Ans--A back-pressure turbine which exhaust steam to an
old boiler header still supplying steam to an old boiler header still supplying
steam to an old lower pressure turbine is called
A topping turbine is an application of - Ans--A back pressure turbine
,Tandem Compound turbines - Ans--Two or more large turbines on one shaft
applied to one generator
Cross Compound Turbines - Ans--Are large turbines in parallel with one
generator on each shaft
In a steam turbine the steams absolute velocity does what in the fixed blades
- Ans--rises
In a steam turbine the steams absolute velocity does what in the moving
blades - Ans--decreases
In a reaction turbine where does the pressure drop - Ans--across the moving
blades
An unbalanced axial thrust will develop on the rotar - Ans--in a steam turbine
with a pressure drop across the moving blades
Reaction turbine blades (moving): - Ans--1) Convert the kinetic energy of the
steam into mechanical energy
2) Convert heat energy into kinetic energy
3) Are nozzle shaped
A reaction turbine results in a long machine due to a large number of
alternate rows of - Ans--fixed and moving blades
Pressure-velocity compounded turbine - Ans--A turbine that expands the
steam in two or more sets of nozzles in series, each set having velocity-
compounded blades to receive the steam issuing from the nozzles
In pressure compound steam turbine - Ans--1)The expansion of steam from
boiler pressure to exhaust pressure is carried out in a number of steps or
stages
2)Each stage has a set of nozzles and a row of blades
4) The rows of moving blades are separated from each other by partitions or
diaphragms into which the nozzles are set
, Velocity compounding in a steam turbine - Ans--one of the nozzles expands
the steam from initial to exhaust pressure
In a condensing-bleeder turbine up to 20% of the total steam flow may be
bled off. What is the bleed-steam used for. - Ans--feed water heating
A condensing-bleeder turbine can bleed up to ______ of the total steam
flow. - Ans--0.2
The primary purpose of a back-pressure turbine is electrical generation -
Ans--false
In a back-pressure turbine the process steam pressure is - Ans--Kept
constant and the generator output depends on the demand for process
steam
Extraction turbines are turbines where steam is extracted at one or more
points at constant _________. - Ans--Pressure
Labyrinth seals are - Ans--4) Made of brass or stainless steel
5) Use on larger diameter turbine shaft
A steam turbine water seal is used ________ to insure that no air leaks in
along the shaft. - Ans--at speed above 2000 rev/min
On larger turbines, the _________ is split in a horizontal direction. - Ans--
cylinder
It is general practice to let the thickness of the walls and flanges
___________ from inlet to exhaust end of a steam turbine casing. - Ans--
decrease in size
Materials at the given maximum temperature and under constant pressure
continue to deform with very slowly increasing strain of the material; this
phenomenon is called _________________. - Ans--creep
Steam turbine casing joints are made steam tight by matching _______
exactly. - Ans--flange faces
And Correct Answers
In an impulse steam turbine nozzle, the following events take place - Ans--1)
The steam pressure decreases
2) The enthalpy of the steam decreases
3) The velocity of the steam increases
4) The volume of the steam increases
Turbine nozzles convert heat energy into: - Ans--Kinetic Energy
The purpose of the bucket or moving blade on the rotor is to convert the
____________ energy of the steam into ________ energy - Ans--Kinetic
into mechanical
In an impulse turbine as the steam passes through the moving blades the
________ drops but the ______ remains the same. - Ans--Velocity drops
and pressure remains the same
The pressure at the outlet from the moving blades is the same as the
pressure at the inlet to the moving blades in __________ turbine. - Ans--An
impulse turbine
Steam turbine stationary nozzles serve to - Ans--1) Decrease steam
pressure
4) Increase steam velocity
On an extraction turbine the extraction pressure is - Ans--Maintained
Topping Turbine - Ans--A back-pressure turbine which exhaust steam to an
old boiler header still supplying steam to an old boiler header still supplying
steam to an old lower pressure turbine is called
A topping turbine is an application of - Ans--A back pressure turbine
,Tandem Compound turbines - Ans--Two or more large turbines on one shaft
applied to one generator
Cross Compound Turbines - Ans--Are large turbines in parallel with one
generator on each shaft
In a steam turbine the steams absolute velocity does what in the fixed blades
- Ans--rises
In a steam turbine the steams absolute velocity does what in the moving
blades - Ans--decreases
In a reaction turbine where does the pressure drop - Ans--across the moving
blades
An unbalanced axial thrust will develop on the rotar - Ans--in a steam turbine
with a pressure drop across the moving blades
Reaction turbine blades (moving): - Ans--1) Convert the kinetic energy of the
steam into mechanical energy
2) Convert heat energy into kinetic energy
3) Are nozzle shaped
A reaction turbine results in a long machine due to a large number of
alternate rows of - Ans--fixed and moving blades
Pressure-velocity compounded turbine - Ans--A turbine that expands the
steam in two or more sets of nozzles in series, each set having velocity-
compounded blades to receive the steam issuing from the nozzles
In pressure compound steam turbine - Ans--1)The expansion of steam from
boiler pressure to exhaust pressure is carried out in a number of steps or
stages
2)Each stage has a set of nozzles and a row of blades
4) The rows of moving blades are separated from each other by partitions or
diaphragms into which the nozzles are set
, Velocity compounding in a steam turbine - Ans--one of the nozzles expands
the steam from initial to exhaust pressure
In a condensing-bleeder turbine up to 20% of the total steam flow may be
bled off. What is the bleed-steam used for. - Ans--feed water heating
A condensing-bleeder turbine can bleed up to ______ of the total steam
flow. - Ans--0.2
The primary purpose of a back-pressure turbine is electrical generation -
Ans--false
In a back-pressure turbine the process steam pressure is - Ans--Kept
constant and the generator output depends on the demand for process
steam
Extraction turbines are turbines where steam is extracted at one or more
points at constant _________. - Ans--Pressure
Labyrinth seals are - Ans--4) Made of brass or stainless steel
5) Use on larger diameter turbine shaft
A steam turbine water seal is used ________ to insure that no air leaks in
along the shaft. - Ans--at speed above 2000 rev/min
On larger turbines, the _________ is split in a horizontal direction. - Ans--
cylinder
It is general practice to let the thickness of the walls and flanges
___________ from inlet to exhaust end of a steam turbine casing. - Ans--
decrease in size
Materials at the given maximum temperature and under constant pressure
continue to deform with very slowly increasing strain of the material; this
phenomenon is called _________________. - Ans--creep
Steam turbine casing joints are made steam tight by matching _______
exactly. - Ans--flange faces
